Die for pointing metal-drills



(No Model.)

P. H. RICHARDS. DIE FOR POINTINGMETAL DRILLS.

Patented Mar. 28, 1893.

lawn/ion UNITED STATES PATENT OFFICE.

FRANCIS H. RICHARDS, OF HARTFORD, CONNECTICUT.

DIE FOR POINTING METAL-DRILLS.

SPECIFICATION forming part of Letters Patent No. 494,226, dated March28, 1893.

Application filed March 29, 1892.

To all whom it may concern.-

Be it known that I, FRANCIS H. RICHARDS, a citizen of the United States,residing at Hartford, in the county of Hartford and State ofConnecticut, have invented certain new and useful Improvements in Diesfor Pointing Metal-Drills, of which the following is a specification.

This invention relates to dies for pointing metal-drills of the classdescribed in my application, Serial No. 426,434, filed March 25, 1892;the object being to furnish a pair of dies whereby one end of adrill-blank may be spread to broaden the cutting-lips in the normalplane thereof, to give the required clearance.

In the drawings accompanying and forming a part of this specification,Figure 1 is a front elevation of apair of drill-pointing dies embodyingmy invention. Fig. 2 is a plan view of the lower die. Figs. 3, 4 and 5are vertical sections, in lines a a, b b, and c c of Fig. 2. Fig. 6 isan end View, and Fig. 7 a side view, of a drill pointed by means of thedies. Figs. 8, 9 and 10 are sections of the drill, in lines a a, b b,and c a, respectively, of Fig. 7, and correspond to the sections of thelower die, Figs. 3, 4 and 5, respectively.

Similar characters designate like parts in all the figures.

The improved metal-drill shown in Figs. 6 to 10, inclusive, is formed ofa drillrod consisting of two oppositely-disposed quadrantsections, 13and 15, having their opposite faces in planes which intersect at theaxis of the drill, and are preferably, as herein shown, at

right angles to each other. The two quadrant-sections join at the axisof the drill, being there connected by the thin web 16. The drill isspread for some distance backward from the point thereof, to give therequired relief, the total amount of this relief being represented inFigs. 6 and 8 by the space between the dotted lines 6 and 9. At somedistance back from the point of the drill, as for instance, at the lineb b, the relief is somewhat less in amount, being represented at v v inFig. 9; while still farther back, as at the line 0' c, the relief isstill less, as indicated at w a: in Fig. 10.

The manner in which the drill-rod is spread Serial No. 426,952. (Nomodel.)

to form the relieved cutting-points 3 and 5, respectively, is byspreading or throwing out the metal in a plane parallel with the faces,2 and 4, of the quadrant-sections 13 and 15, said plane beingrepresented by the line h h, Fig. 8. The spreading of the blank beginsat about the line 0 c, Fig. 7, and increases regularly from thence tothe point of the drill. As a means for obtaining the required wideningof the drill-point without misshaping the cutting-faces, 2 and 4, of thedrill, the opposite faces, 6 and 8, of said quadrant-sections are thrownforward as indicated at 7 and 9, thereby furnishing the metal requiredfor filling out the cutting-edges in the plane, h h, described. Thiswill be understood by comparison of the several figures of the drawings,in connection with the preceding description; reference being had, also,to my aforesaid application.

My. present invention relates to dies constructed to shape the end ofthe drill-rod, B, to have relieved cutting-edges of the character setforth. The dies consist of a lower die, designated in a general way byF, and an upper die, designated by G. For holding the dies in place in aforging machine (not shown), the upper corners thereof may have theusual dovetailed form, as shown in Figs. 1, 3, 4 and 5. As a means forproperly guiding the upper die relatively to the lower die, this die hasthe ribs 21 21, whose inner inclined faces, 22 22, engage and serve asguides for the upper die G, as will be understood from Fig. 1.

The drill-forming depressions, 13' and 15', of the two dies F and G, arealike, except that the same are,oppositely-disposed. The face 2' of thedie G is that on which the face 2 of the drill B is spread; and the face4 of the die F is that on which the face 4 of said drill is spread,during the drill-pointing operation; these two faces, when the dies aretogether, as in Fig. 1, correspond to the plane h h of said drill-faces2 and 4. The sections cm, 1117, and c 0, shown in Figs. 3, 4, and 5,respectively, are of the lower die only; but as the drillformingdepressions of both dies are of similar form, a detailed description ofone of them will be sufficient.

The concaved face 30 of the die corresponds to the relieved surfaces 12and 14: of the drill, being slightly tapered from the front of the die,(where it corresponds to the normal section of the drill-rod 13,) towardthe back thereof. By comparing the curved line 30, Fig. 5, with the twocircles e and g, and these with the same line and circles in Figs. 4 and3, it will be seen that the relief increases from the line 0 c to thelines I) b and Ct at, Fig. 2. From a corresponding comparison of theline 9' with the circles e and g in Figs. 5, 4E, and 3, it will beseenhow the face 9' (Figs. 1 and 2) diverges from the plane of line it,from the front toward the rearward side of the die. This divergenceshould be sufficient to reduce the cross-sectional area of the space 15in the plane a a to a less area than that of said space at the front ofthe die, so that in the forging operation the space 15 at the rearwardend thereof will be entirely filled with metal, notwithstanding theallowance necessary on account of the slight longitudinal extension ofthe drill-rod under the pressure of the dies. For this reason, thesurface 9 is shown warped away from the planet 2', by a greater distancethan the surface is warped away from the circle g. By this means asufficient amount of the metal is thrown forward to entirely fill thedie at the point 12 and to assure the proper filling out of thedrill-edges 12 and 14, Fig. 7, throughout the relieved portion of thelength of the drill.

When, in using the dies, the heated blank is placed in them and forceisapplied thereto, the metal naturally flows in the direction of leastresistance, which direction is in the plane of the die-faces anddirectly tends, therefore, to spread the metal in the proper direction.

The dies having been properly fixed in a suitable forging machine, asfor instance, a drop-press, the heated drill-rod is placed on the lowerdie and struck by the upper die after the usual manner of drop-forging,thereby forcing-the metal, by means of the warped diefaces hereinbeforedescribed, to have the shape of the longitudinally and circumferentiallyrelieved drill-point shown in Figs. 6 and 7 and more fully described inmy aforesaid application. In practice, to attain the best results it isdeemed preferable when first pointing the drill-blank to insert thepoint of the blank to about the line 0 c, Fig. 2, striking it one blowat this point; next, (after re-heating the blank,- should this berequired,) the drill-blank is advanced to about the line b b and struckasecond time, after which it istagain advanced to about the line a a andgiven its final size and shape. The number of these successiveoperations required in any particular case can readily be determined byexperiment, due regard being had to the nature and condition of themetal being operated upon and the extent of the relief to be given tothe drill.

Having thus described my invention, I claim- 1. The improveddrill-pointing dies herein described, consisting in a pair of dieshaving the corresponding oppositely-disposed drillforming spaces eachcorresponding on one side thereof to the plane of the die-faces, andhaving the other side thereof warped substantially as described forbroadening and thinning the quadrant-sections of the drill-blank,substantially as described.

2. The improved drill-pointing die herein described, consisting in a diehaving the concaved face corresponding to the relieved surface of thedrill, and the warped surface for spreading the drill-point,substantially as shown and described.

FRANCIS I-l. RICHARDS.

Witnesses:

HENRY L. REOKARD, HANS MALLNER.

